1. Field of the Invention
The present invention relates to an image forming apparatus equipped with a fixing unit.
2. Description of the Related Art
In general, an image forming apparatus utilizing the electrophotographic process forms an unfixed toner image on a recording medium with an image forming unit and heats and applies pressure to the unfixed toner image with a fixing unit so as to fix the unfixed toner image onto the recording medium.
Some types of toner used in the image forming apparatuses contain a releasing wax so as to produce effects such as adjustment of the gloss of an image formed on a recording medium and dispersibility of a pigment. The releasing wax is liquefied when the recording medium is heated and subjected to the pressure by the fixing unit. Although most of the liquefied releasing wax together with the fused toner is attached to the recording medium and solidified, part of the liquefied releasing wax is gasified. The gasified releasing wax may become fine particles in the liquid phase or the solid phase depending on the ambient temperature and may be attracted to members in a space through which the recording medium is conveyed while moving in the space with the recording medium. In particular, when the releasing wax is attracted to rollers that convey the recording medium on the downstream side of the fixing unit in a direction in which the recording medium is conveyed, the performance of conveying the recording medium may be degraded.
In order to address this, Japanese Patent Laid-Open No. 2011-237555 discloses a structure that includes a housing, a conveyance rotary member, and a closing member. The housing houses a heating rotary member and has an exit that is open on the downstream side in a recording medium conveyance direction, in which a transfer material is conveyed. The conveyance rotary member guides conveyance of the transfer material provided near the exit in the housing. The closing member closes a space between the housing and the transfer rotary member.
However, since it is required that a gap be provided between the closing member described in Japanese Patent Laid-Open No. 2011-237555 and a recording medium, part of a releasing wax component may move through the gap together with the recording medium toward the downstream side of a fixing unit in the recording medium conveyance direction and may be attracted to conveyance rollers. Accordingly, the present invention provides an image forming apparatus in which the releasing wax component is unlikely to be attracted to the conveyance rollers disposed downstream of the fixing unit in the recording medium conveyance direction.